A power system for an electric vehicle, an electric vehicle and a motor controller for an electric vehicle are provided. The power system includes: a power battery (10); a charge-discharge socket (20); a three-level bidirectional DC-AC module (30); a motor control switch (40); a charge-discharge control module (50) having a first terminal connected with an AC terminal of the three-level bidirectional DC-AC module (30) and a second terminal connected with the charge-discharge socket (20); and a control module (60) connected with a third terminal of the charge-discharge control module (50) and a third terminal of the motor control switch (40), and configured to control the charge-discharge control module (50) and the motor control switch (40) according to a current working mode of the power system.